Fifth wheel locking mechanism



United States Patent [72] Inventor Perluil N. Nelson [56] References Citd Galesburg, "limb UNITED STATES PATENTS gm zfi 1,981,233 11/1934 Harris280/434 Patented 1970 2,426,002 8/1947- Den Besten 280/434 2,456,82612/1948 Fontaine 280/434 [73] Ewing as 2,610,069 9/1952 Ketel 280/434Blackhawk Company Rock Island, Illinoi Primary Examiner-Leo FriagliaAttorney-Edward C. Threedy [54] FIFTH WHEEL f m MECHANISM ABSTRACT: Alocking mechanism for the coupling pin con- 4 Claims 2 Drawmg Figsnection between a tractor unit and a semitrailer which pro- [52] U.S.Cl. 280/434 vides a positive three point bearing contact between the[51] Int. Cl. B62d 53/12! coupling pin and the connecting plate, thelatter including an {50] Field of Search 280/434, automatic locking unitmovable in response to the position of 438 the coupling pin relative tothe connecting plate.

Patentd Nov. 10, 1970 3,539,202

PERM/L lV AELSM An articulated connection between'two' coupling partscomprising a coupling'pin' secured to one'partand a receiving connectingplate including a locking assembly carriedhy' the other part. Thelocking assembly comprises a'rtiova'blc look a'rm' responsive to thepresence of the couplingpin within a receiving passage formed in theconnecting plate and a manually operated'latch bolt for releasablylatching'thelock arm about thecoupling pin.

DETAILED DESCRIPTION The invention will be best understood byreference'tothe' accompanying drawing in which the preferred form ofconstruction of the invention is shown; and in'whi'ch':

FIG. 1 is a topplan-view of so'muc'h of the invention and itsenvironmentnecessary for an understanding. of its operation, the coupling pin beingshown in section and'the connecting plate supporting members being shownin dotted lines, and

FIG. 2 is a top plan view similarto FlG. l but showing the lockingassembly in its unlocked or coupling pin receiving position Scmitrailcrcoupling pin locking mechanisms or fifthwheel connectors, as theyareltnown inth'e art, normally include a connector plate carried at rearof a tractor and a cou'pling pin carried by and depending from a traileru'nit such'as is disclosed in my US. Pat/No:- 3,352,571issucd Nov. l4.1967. These general structural parts have not been shown in detail inthe drawings of this application, and will not be described exccpt forreference to their environment respecting thep'rcscnt invention in thedrawings there is shown in top plan view a connecting. plate normallysupported on 'rails- 11 (shown in dotted lines) carried in a-generalhorizontal'pla'ne" on therear of a tractor. The plate 10 has formedtherein a rearwardly extend-- ing dove-tailed "entry slot 12 whichterminates intoa semi'cir cular center opening 13. Thep'lateIOisprovided witha raised peripheral edgel4 ove'r which acov'er'not-shown) is a'dapted' to be placed to enclose the locking assemblyhereinafter described.

Fixedly mounted on the plate 10'andwithinthe raised peripheral edgeM-and exterrding-"seinicircularlyabout-and'in alignment withtheopeningliis-araiscd rail' [5. The 'rail. I5 has formed therethrou'gha-'passagefdimwhich is-sli'd'ably journaled a plunger I7. This plunger17 moves through-a housing 18 mounted on the plate-1'0 between the railand the raised periphcraledge 1'4 as'-seen in"FlG"S 1 'and2. The plunger17 is normally urgc'dotitwar'dly of itshousinglfiby an expansion spring19 contained"thereimwith th'e-dista'rrcelof' movement determined bythelength of'a slot-ififormed' in the top wall of the housing [Sandthrough which projects apin' 'Zl fixed to the inner endof the plurrger'17i- The pin 21 also'projects througha slot IZ formed in one arm 23 of atoggle link 2'4. The togglelin'k' Z i' is pivotedabout' a stud 25 andmoves-inresponseto thedirectional'movement of the plunger [7 such thatitsopposite elongated"arm""26 is moved toward and away from thecenter'openinglBLThe free end of the arm 26-is pivotally connectedtoa'secondlinls arm 27, which has its opposite free' endpivotally-connected as at 28 to a finger-29 provided by thecouplingpirilocloarmfilll As shown in the drawings,'the coupling pin'lookarmiSO' comprises a semicircular me'm'berwhich,'togethenwiththe: raisedrail 15, 'comprises'a circularretain'ing collarforthe coupling pin 26.The lock arm 3'0- hasl-on'eend pivotall'yzconnected as at 31 to theplate 10, and its opposite free'end formed to provide a' laterallyextending flange'membe'rfc'az which has one side'edge 33 tapere'd fora'purpose'hereinafter" explained.

As shown inFIGL Z' the'locking-rnechanismofthe invention is in itsunlocked orcoup'lingipinreceivingposition. In such position theplungerl'7 under the actionof'the'spring 19 has been moved through thehousingl8 -aswell asthe openingfG formed in the rail I IStoa pointwherein r'reeend 34 is exposed Within the center openin'glB formed ihtheplate It). By thepositioning of the plunger l'l 'thet'oggle link 24 hasbeen pivoted about the stud '25 such th'atthe link arms 26 and 27 haveefi'e'cted a pivoted movement of the lock arm into a retracted positionoutof the entry slot 12 arid against a stop pin 35 carried bythe plate10.

As the trailer and tractor unit's are' 'rr'ioved'to'gether the dependingcoupling pin'26 will move throughthe-entry slot 12 and into thec'enteropening 13 against the freeend 34' of the plunger 17 As the coupling pin36 moves into the center opening 13 it will force the plunger 17inwardly of its'housing 18 against the spring 19 and through thepin 21the plunger 17 will pivot the toggle link 24 in a clockwise direction,as shown,

of rubber or the like.

it should'be'noted thatath'e'rail l5, aswell as the loclting arm 30',are each provided with arcuated sectional bearing elements 37' and 38;respectively, which when the locking arr'n'30 is" in its lockingposition bear against the peripheral edge of thecoupling-pin36;'tl1us*providing a positive three point contacttherewith.

"Carried bythe plate 10' and extending radially with' respect 3o to'thecenter openinglB, and-spaced therefrom is a-secon'd housing 39'which-slidahiy contains a latch lever '40. One end of the latch lcver4'0is pivo't'ally connected as at-4ll toonc end of an operating "handle4 2;which is adapted to be pivoted "about a fixed pivotpindBSThe 'free' endof'thehandle'42 is movable through a locking bracket 44 which isprovided with" arteries-of ope'ningsj45 through which a locking elementmay be'p'rojected to secure the handle-42in any pivoted position Thefree end of the latch lever'40 provides anenlarg'ed head 46 which hasone sedge 47 tapered to: correspond to the tapered edge 3 3 of thelat'ch'finger'BTZi- The latch lever 4'0 is normally nrged into-aconnectingposition between its en:

1ar'g'edhead'46 and -the-lateh finger'i by a compression spring 48'contained within the housing! 391 The distance of movementbf the latchlever? through the housing3'9 is guided apin l earriedthereby whichprojects th'rough an elongated sIot-SOformed-in the top walliof thehousing;

When' the lock arm 3'0"has*been pivoted,- as hereinbe'fore 1 described;-itw'illbeheld in place bymanual movement of the constructionfor carryingmyinvention into effecL this-iscapableof'variationand modification"without departing from the spiri t ofthe ihventioni l, therefore.'do'not' wish to'belimited to the'pr'ecise detailsof constructionsetfbrth, but desiret'o'avail myself of such variations andmodifications as corne wi'thinthe I scopeotth'e app'endedclaims:

I. claim: p ll'. A fiftli Wl'ieel locking rn'echanism between a'semit'railer collar,

'b'. saidicollarhavinga'fixed portion'carried 'byitheconnect ing pl'ate"and extendingisemicircularly aboutth'e'opening formed therein,

c. a movable corresponding semicircular portion pivotally carried by theconnecting plate to one side of the entranceway and movable therethroughinto contact with the connecting pin, 7

d moving means connected to said movable semicircular portion of saidlocking means for pivoting it into and out of its entrance-blockingposition,

e. means movably carried by the connecting plate and connected to saidmoving means and responsive to the movement of the coupling pin into andout of the center opening formed in the connecting plate for operatingsaid moving means so as to pivot said movable semicircular portion ofsaid locking means through the entranceway into and out of lockingposition about the locking pin, and

f. a manually operated latching member carried by the connecting platefor securing said movable portion of said locking means in lockedposition about the coupling pin when the latter is moved into the centeropening of the connecting plate.

2. A fifth wheel locking mechanism as defined by claim 1 wherein saidmovingmeans comprises a toggle link assembly connected between saidmovable semicircular portion of said locking means and said operatingmeans for pivoting said movable semicircular portion of said lockingmeans through the entranceway into and out of latching position aboutthe coupling pin.

3. A fifth wheel locking mechanism as defined by claim 1 wherein saidoperating means comprises a spring-urged actuating plunger carried bythe connectingplate and having one end normally positioned within thecenter opening and in radial alignment with the entranceway. with theplunger movable by the coupling pin out of the center opening so as tooperate said moving means to pivot said movable semicircular portion ofsaid locking means through the entranceway into and out of latchingposition about the coupling pin.

4. A fifth wheel locking mechanism as defined by claim 3 wherein saidmoving means comprises a toggle link assembly connected between saidmovable semicircular portion of said locking means and said spring-urgedactuating plunger for pivoting said movable semicircular portion of saidlocking means through the entranceway into and out of latching positionabout the coupling pin.

